Understanding Types of DVDs

DVDs, or "Digital Versatile Discs," are used for video and data storage. For data storage, a single-sided DVD can hold about 4.7 GB. (If it's double-sided you obviously can get 9.4 GB onto it.) You really can't provide a capacity when a DVD is formatted for video, though, because of a combination of factors like the type of DVD it is, the way the video was produced, the way the audio in the video was produced, etc. For example, a standard single-sided 4.7 GB disk at maximum DVD quality can hold about an hour of standard video/audio. On the other hand, if you're content with VHS quality, you might be able to get nine hours on the same disc.

There are several types of DVDs. As mentioned previously, there are single-sided and double-sided DVDs. Beyond that, those that are currently popular include the DVD-R ("R" for Recordable) and the DVD+R. The "minus" version and the "plus" version both give you a write-once capability of up to 4.7 GB, and the major difference is simply the specifications used to format each type. In general, with modern equipment they can be used interchangeably.

The other pair of popular DVDs are the DVD-RW ("RW" for ReWritable) and the DVD+RW. These "RW" types of discs can be written to hundreds of times before starting to degrade. (Some literature puts the figure closer to 1,000 rewrites.) As with the minus and plus versions of the recordable DVDs, there isn't too much different between a DVD-RW and a DVD+RW except for the fact that "plus" version does offer faster writing, a more robust file structure, and support for drag-and-drop desktop files.

In general, the DVD-R seems to be the most compatible computer-burned DVD format, but if your DVD drive supports the "RW" types, you'll have a bit more versatility by using DVD+RW.

Finally, there is the DVD-ROM, which is created by a manufacturer and can only be read, not written.

 This tip (13024) applies to Windows 7, 8, and 10.